Additives for lubricants



United States Patent 3,277,004 ADDITIVES FOR LUBRICANTS Sidney Schifi,Barflesville, 0kla., assignor to Phillips Petroleum Company, acorporation of Delaware 7 No Drawing. Filed Nov. 30, 1964, Ser. No.414,855 16 Claims. (Cl. 25233) This invention relates to improvedadditives for lubricants. In one aspect this invention relates tomethods of preparing said improved additives. In another aspect thisinvention relates to lubricant compositions containing said improvedadditives.

At the present time it is common practice to enhance or modify certainof the properties of lubricating oils through the use of variousadditives or improvement agents. The lubricating oils employed ininternal combustion engines, such as automotive, light aircraft, anddiesel engines in particular, require the use of additive agents torender them serviceable under the adverse environmental conditionsencountered in these engines. Among the various additives employed inmodern engine oils, one of the most important is the type which acts toprevent accumulation of sludge in the crankcase and on the cylinderwalls, thereby preventing sticking of the piston rings, and theformation of varnish-like coating on the pistons and cylinder walls.Because of their general function of maintaining a clean engine,additives of this nature are termed detergents, although it is nowunderstood that they have little utility in cleaning a dirty engine butby virtue of dispersant activity preventor greatly retard enginefouling.

Metal petroleum sulfonates have been widely used as detergent additivesfor lubricating oils. Various methods have been employed for thepreparation of said metal petroleum sulfonates. Many of these processesare quite complex involving a large number of treating steps. Generallyspeaking, said methods comprise the sulfonation of a petroleum fractionto obtain a mixture of sulfonic acids and unsulfonated oils, andneutralizing the reaction mixture with the carbonate, oxide, orhydroxide of a metal to obtain a mixture of the corresponding metalpetroleum sulfonate and unsulfonated oils. Metals which have been usedin such processes include the alkaline earth metals, such as calcium,and other metals, including lead, nickel, cobalt, tin, zinc, etc.

In addition to detergent properties, it would be highly desirable forsuch detergent additives to have good rust inhibiting properties. I havenow discovered that a superior lead petroleum sulfonate having excellentrust inhibiting properties as well as good detergent properties can beprepared by neutralizing the acid oil obtained in the sulfonation stepwith both lead oxide and lead acetate. The lead petroleum sulfonateprepared in this manner is superior to lead petroleum sulfonates whichare prepared by using either lead oxide or lead acetate alone.

Thus, broadly speaking, the present invention resides in a superior leadpetroleum sulfonate which has been prepared by neutralizing the acid oilobtained in the sulfonation step with both lead oxide and lead acetate;methods of preparing said improved lead petroleum sulfonates; andlubricant compositions containing said-superior lead petroleumsulfonates. 7

An object of this invention is to provide an improved or superior leadpetroleum sulfonate which is useful as an additive in lubricantcompositions. Another object of this invention is to provide a processfor preparing said 3 ,Z77,004 Patented Oct; 4, 1966 improved or superiorlead petroleum sulfonates. Still another object of this invention is toprovide an improved lubricant composition containing said superior leadpetroleum sulfonate. Other aspects, objects, and advantages of theinvention will be apparent to those skilled in the art in view of thisdisclosure. 1

Thus, according to the invention, there is provided a process forproducing a superior lead petroleum sulfonate, useful as an additive forlubricants, which process comprises: sulfonating a petroleum hydrocarbonfraction having a viscosity within the range of 90 to 720 SUS at 210 F.and a viscosity index of at least about 85; neutralizing the reactionproduct with a mixture of lead oxide and lead acetate, said lead oxidebeing present in said mixture in an amount suflicient to supply from 12to 90 weight percent and said. lead acetate being present in saidmixture inan amount'sufiicient to supply from 88 to 10 weight tralizinngthe reaction product with a mixture of lead oxide and lead acetate, saidlead oxide being present in said mixture in an amount sufiicient tosupply from 12 to 90 Weight percent and said lead acetate being presentin said mixture in an amount suflicient to supply from 88 to 10 weightpercent of the total amount of lead milliequivalents present; andrecovering a mixture of said lead petroleum sulfonate and unsulfonatedoil from said neutralized reaction product as said additive.

' Still further according to the invention, there is pro vided alubricating oil composition comprising a lubricating oil base stockcontaining from 0.2 to about 30 weight percent of a lead petroleumsulfonate obtained by: sulfonating a petroleum hydrocarbon fractionhaving a viscosity within the range of 90 to 720 SUS at 210 F. and

in an amount sufiicient to supply from 88 to 10 weight percent of. thetotal amount of lead milliequivalents present; and recovering theresulting lead petroleum sulfonate.

It is to be noted that both lead oxide and lead acetate are used in theneutralization step of the invention. As clearly shown by data given inthe examples hereinafter, lead petroleum sulfonates prepared by usingboth lead oxide andlead acetate to neutralize the acid oil obtained inthe sulfouation step are markedly superior to lead petroleum sulfonatesproduced when either lead oxide or lead acetate is used alone toneutralize said acid oil. Said data clearly show that when both leadoxide and lead acetate are used there is obtained a synergistic effectwith respect to rust inhibition properties as compared to using eitherlead oxideor lead acetate alone, the same total mi-lliequivalents oflead being used in all instances.

In" the practice of the invention, said lead oxide and said lead acetateare used in amounts, with respect to each other, whereby of the totalamount of lead milliequivalents present, lead oxide is present in anamount sufl'icient to supply from 12 to 90 weight percent and leadacetate is present in an amount sufiicient to supply from 88 to weightpercent of said total amount of lead. Preferably, the lead oxide ispresent in an amount sufiicient to supply from 20 to 88 weight percentand said lead acetate is present in an amount sufiicient to supply from80 to 12 weight percent of said total amount of lead present. Still morepreferably, the lead oxide is present in an amount suflicient to supplyfrom 50 to 87 weight percent and said lead acetate is present in anamount suflicient to supply from 50 to 13 weight percent of said totalamount of lead present.

Said total amount of lead oxide and lead acetate which is used in thepractice of the invention is an amount which is at least sufiicient toessentially neutralize the total acidity of the reaction product fromthe sulfonation step, i.e., an amount which is stoichiometricallyequivalent to said total acidity. Preferably, said total amount of saidlead compounds. Will be an amount which is sufiicient to supply at leastabout 1.13, preferably at least about 1.3, and more preferably at leastabout 1.4 milliequivalents of lead per milliequivalent of said totalacidity. Usually not more than 2.5, more usually not more than 2 orless, total milliequivalents of lead per milliequivalent of totalacidity are use-d in the neutralization step. However, it is within thescope of the invention to use more than 2.5, e.g., up to aboutS or more,milliequivalents of lead per milliequivalent of total acidity. When themilliequivalents of lead used per milliequivalent of total acidity is inthe order of 2 or more, the product obtained is sometimes a gel whichpresents ditficulties in dispersing same in the base lubricating oil.However, this difiiculty (when it occurs) can be readily avoided byblending the base lubricating oil into the, hydrocarbon diluted productafter the filtration step and before removal of said hydrocar bondiluent. Said filtration step is described hereinafter.

As used herein and in the claims, unless otherwise spephalt, or bothparaflin and asphalt'are present in the residue after distillation ofthe lighter components.

Mexican and Mid-Continent petroleums respectively.

The residual material discarded from the propane fractionation stepcontains the rejected asphalt and more aromatic oils. The lube oilfraction, recovered in a propane fractionation step after removal of theSAE 50 lube stock,

I sulfuric acid can vary from 10 weight percent to 40 weight cified, theterm total acidity refers to the titratable acidity, reported as H 80and determined as follows. Two grams of the acid oil obtained in thesulfonation step are weighed into a 250 ml. flask and 15 ml. of benzene,15 ml. of isopropyl alcohol, and ml. of water are added. The mixture isshaken well and three drops of phenolphthalein indicator are added. Themixture is then titrated with standard 0.1 N NaOH until a permanent pinkcolor remains in the water layer. From the above, total acidity asweight percent where V=ml. of NaOH, N=norma1i ty of NaOH, and W=grams ofsample.

A wide variety of oils can be used in the practice of the invention asthe charge oil in preparing the lead petroleum sulfonates of theinvention. Said charge oil is selected from the more viscous brightstock fractions of petroleum. A petroleum fraction having a viscosity ofat least 90 SUS at 210. Fqwill produce a lead petroleum sulfonate whichis satisfactory for many purposes. The deasphalted and solvent refinedpetroleum fractions having a viscosity of about 140 to about 720 SUS at210 F; are preferred. A presently more preferred sulfonation chargestock is a propane fractionated, solvent extracted, and dewaxedMid-Continent oil of about 200 to about 230 SUS at 210 F. and having aviscosity index of about 85 to 100, or even higher.

A Mid-Continent oil is more precisely defined as a mixed base orintermediate base oil in The Science of Petroleum, volume 1, page 7,Oxford University Press, London,- New York and Toronto, 1938. The baseof a crude petroleum is defined therein as follows:

The base of a crude petroleum is descriptive of the chemical nature ofits main constituents. A petroleum may be described as parafiin base,asphalt base, or mixed base (intermediate base), according as paraffinwax, as-

percent excess S0 However, it is usually preferred to use commercialfuming sulfuric acid which contains about 20 weight percent excess S0Liquid S0 i.e., liquid 50;; in liquid S0 is the presently preferredsulfonatingagent for use in the practice of the invention. Such liquidS0 is commercially available.

When '20 percent fuming sulfuric acid is used as the sulfonating agent,the acid-oil ratio can be in the range of from about 0.1 :1 to about0.7:1, or even 1:1 to produce the petroleum sulfonates of the invention.A preferred range of acid-oil ratios is in the range of about 0.3 to

about 0.6:1. When liquid SO; in liquid S0 is the S111? fonation agent,the 80;, to oil weight ratios are maintained equivalent to thoseavailable from the. 20 percent fuming sulfuric acid values given above.

0.2, preferably about 0.06 to about 0.12:1. Said S0 10 oil ratios can becontrolled by varying the rate of flow of the oil or of the SO-containing medium, or both. The

above given ratios are weight ratios.

fuming sulfuric acid is utilized as the sulfonating agent in order toprovide optimum yield and quality of products. When sulfur trioxide,e.g., sulfur trioxide in sulfur dioxide, is utilized as the sulfonationagent, the reaction rate is greatly accelerated and the reaction hasbeen found to be substantially completed in the time required to. ac-

complish suitable contact of the oil with the sulfur trioxide, usuallyless than about five minutes.

The sulfonation reaction can be carried out at atmospheric pressurealthough'pressures greater or less than atmospheric also can beemployed,.if desired. When using liquid S0 in liquid S0 as thesulfonating agent,

it is preferred to carry out the reaction at suflicient pressure tomaintain the S0 in liquid phase.

The neutralization step in the process of the invention can be carriedout-in any suitable manner for contacting the acid oil, obtained fromthe sulfonation step, and the dual neutralizing agents of the invention.One very satisfactory method simply comprises contacting said acid oilwith both lead oxide and lead acetate in any suitable mix ing vesselemploying conventional mixing means, at a tem perature above about 100F., for a period of time suflicient to eifect the neutralization, andrecovering a mix-.

ture of lead petroleum sulfonates. and unsulfonated oil.

. In a more specific application of the invention, the oil charge stockis intimately contacted with the sulfonation For example, the contactingcan conveniently be' agent. accomplished by mixing the oil andacidstreams, or the oil and liquid 80;, in liquid S0 streams, in acentrifugal pump. When fuming sulfuric acid is'the sulfonation agent,the mixture is passed to a reaction chamber main YP cal representativesof these three classes are Pennsylvanian,

In other words, the to oil ratio can be in the range of about0.02 totained at reaction temperature, through which the mixture passes with aminimum of mixing overa period of time in the range of about 20 to about90 minutes. When liquid sulfur trioxide in liquid sulfur dioxide is thesulfonating agent, the reaction chamber can be partly or whollyby-passed, and a suitable soaking vessel providing a few minutesresidence time (usually not more than about five minutes) can beemployed. The sulfonation step per se forms no part of my invention andany suitable sulfonation technique known to the art can be employed.When liquid S0 in liquid S0 is used as the sulfonating agent, thereactor or soaking zone effluent is passed to a flash tank where the S0is vaporized and substantially completely removed for reuse.

The reaction product effiuent from the reaction chamher or flash tank(depending upon the sulfonation agent used) is neutralized by running itinto an agitated vessel to which there are also added the requiredamounts of lead oxide and lead acetate, a hydrocarbon diluent, andwater. Preferably, said lead oxide and lead acetate are added togetheras a mixture. However, it is within the scope of the invention to addsaid oxide and said acetate separately in the required amounts. Thetemperature of the contents of this neutralizing vessel is not criticalwith respect to neutralization, but is ordinarily held between about 160to 200 F. for a period of time suificient to neutralize the reactionmixture because the subsequent filtering step is greatly benefited byneutralizing at the above temperature.

Suitable hydrocarbon diluents for use in the practice of the inventioninclude Stoddard solvent, kerosine, normal heptane, normal octane,benzene, toluene, and others. Said diluent can be employed in a diluentto acid oil ratio of from 0.5 :1 to 3:1, preferably about 0.75:1 to1.5: 1. Water is usually employed in a water to acid oil ratio of about0.75 :1 to 1.5 :1. Said ratios are volume ratios and are not critical,the actual amounts used being chosen largely as a matter of convenience.

After the neutralization of the acid oil is complete, the neutralizedmixture is then heated to a temperature within the range of about 300 toabout 375 F. to remove the water and at least a portion of thehydrocarbon diluent. The remaining product is then cooled, dissolved inadditional hydrocarbon diluent, and filtered to remove inor ganicsolids. The filtrate from said filtering step is then heated to removesaid diluent therefrom so as to recover the product comprising leadpetroleum sulfonate and unsulfonated oil. If desired, filtration of saiddiluted product can be facilitated by the addition thereto of a filteraid.

The lead petroleum sulfonates can be'separated from the residualunsulfonated oil associated therewith by means of extraction withpropane and/ or butanes under appropriate conditions of temperature andpressure. The light hydrocarbons, propane, isobutane, and normal butane,have been found to have a unique and unexpected selectivity for thisseparation, producing under appropriate conditions, substantiallyash-free oil and oil-free sulfonates. Using propane as the solvent,extraction temperatures of about 150 to about 200 F. are required atpressures of about 640 p.s.i.g. Lower temperatures result in excessiveinclusion of sulfonate in the extract. With normal butane, lowerpressures of about 400 to 500 p.s.i.g. are adequate, but to achieveselectivity, the temperature range must be held between about 290 andabout 305 F. The conditions required when isobutane is required areintermediate those for propane and for normal butane.

The products of this invention can be incorporated into lubricating oilcompositions in several combinations depending upon specific servicerequirements. For example, if desired, in the case of heavy duty oils,such as those used in trucks, buses, and general diesel applications,the oil-free lead petroleum sulfonate can beblended with suitable basestocks. In many general duty crank- 6 case oils, the unfractionatedcombination of lead petroleurn sulfonate and unsulfonated' product oilcan be blended with appropriate base oils. In the case of other generalduty crankcase oils, there can be added to the base oils, suificientoil-free lead petroleum sulfonate to provide adequate detergency,and'unsulfonated product oil substantially in excess of that normallypresent in the unfractionated total product of the sulfonation process.In these variations of blending, the lead petroleum sulfonate componentswill provide high quality oils as required in various ordnance and otherqualification tests and other specifications, and outstandingperformance with respect to sludge formation in stop-and-go engineoperation as well as superior performance with respect to rustinhibition.

Generally speaking, the, product of the invention comprising leadpetroleum sulfonates and unsulfonated oil can be added to the base oilin anamount suflicient to obtain the desired degree of improvementcharacteristics of the base oil. Said product can be added to said baseoil in amounts of about 0.2 to about 30 weight percent of the finishedoil. The concentration of lead petroleum sulfonate alone in the base oilis normally in the range of about 0.1 to about 15 weight percent of thefinished oil and a presently preferred concentration of said'productcomprising lead petroleum sulfonate and .unsulfonated oil is in therange of about 2 to 20 weight percent of the finished oil. A presentlypreferred concentration of lead petroleum sulfonate in the finished oilis in the range of about 1 to about 10 weight percent of the finishedoil.

The following examples will serve to further illustrate the invention.

EXAMPLE'I A lead petroleum sulfonate was prepared from asolvent-refined, dewaxed lubricating oil fraction derived fromMid-Continent petroleum and having the following properties: Viscosityof 4222 SUS at 100 F., viscosity of 212.4 SUS at 210 F., and viscosityindex of 97.3. The charge stock, identified as finished 250 stock, wassulfonated with a 10 percent SO percent S0 mixture in a continuousoperation. The S0 to oil weight ratio was 0.08 and the temperature ofthe reaction was controlled at about 115 F. The total' reaction time was5 minutes, including the mixing and soaking periods. The system wasmaintained in liquid phase at a pressure of -120 p.s.i.g. -Efiluent fromthe sulfonation unit was subjected to a two-stage flash for 50 -80removal.

Eight l'00-gram portions of the acid oil resulting from the SO -S0flashing step were each dissolved in 80 ml. of toluene and 50 ml. ofwater was added to each of the resulting solutions. Leadoxide and/orlead acetate (in amounts togive 116 total milliequivalents of lead) wasadded, the-mixtures were stirred, and heated to 360 F. to strip thetoluene and water. The productwas cooled, redissolved in toluene,filtered, and the filtrate heated to strip the toluene and yield eightproduct additives of lead petroleum sulfonate and unsulfonated oil.

Said eight product additives were tested for .pH and TBN (total basenumber) as described hereinafter.

Said eight product additives were each blended at a 4 weight percentconcentration into eight individual samples of a commercial SAE 10lubricating oil stock con-.

taining 0.9 weight percent of Lubrizol 1360 (zinc alkyldithiophosphate). The eight resulting lubricating oil compositions werethen tested for rust in hibiting properties in accordance with amodified version of ASTM D665-60, Procedure A. In said modified version,30 ml. of 1 percent'acetic acid was used instead of 30 ml. of distilledwater, and-stirring of the oil-acid mixture was for 16 hours instead of24 hours. A control test (Run No. 9) was also run on said base SAE 10lubricating oil stock which did not contain any additive of theinvention. The results of the above tests are set forth in Table Ibelow.

Table I Weight Percent Pb Run Lead Lead Rust No. Oxide Acetate pH TBN 1Ratmg Meq. Meq. as as PbO Pb(Ac)z 100 0 3. 8 3 10. 90. 9 9. 1 4. 7 17. 05 16 86. 2 13. 8 4. 9 15. 1 8. 5 29 1 75. 0 25. 0 4. 4 13. 4 8 58 50.050. 0 4. 3 14. 4 7. 5 93 19. 8 80. 2 4. 3 16. 2 7 105. 5 9. 1 90. 9 5. 216. 5 5 8 116 0 100 4. 5 17. 5 5. 5 9 (control) 4. 25

1 TBN=total base number 2 10 is a perfect rating The above data showconclusively that a synergistic effect is obtained when both lead oxideand lead acetate are used asneutralizing agents, i.e., when using bothlead oxide and lead acetate the lead petroleum sulfonate productobtained has better rust inhibiting properties than the lead petroleumsulfonate productobtained when using either lead oxide or lea-d acetatealone. A plot of the above data plotting rust ratings vs. total lead inweight percent of lead as lead oxide and weight percent as lead acetateshows that when the neutralizing mixture contains from about 12 to about90 weight percent of lead oxide and from about 88 to about 10 weightpercent lead acetate the rust rating of the lead petroleum sulfonateproduct will be above 5.5.

EXAMPLE H Another series of runs was carried out -to determine theeflect of the quantity of the neutralizing mixture of the invention onthe quality of the lead petroleum sulfonate product.

A lead petroleum sulfonate was prepared from a solvent refined, dewaxedlubricating oil fraction essentially like that used in Example I andhaving a SUS viscosity at 100 F. of 4028, a SUS viscosity at 210 F. of205.4, and a viscosity index of 97.1. Said lubricating oil fraction wassulfonated and the acid oil product recovered in essentially the samemanner as described in Example I.

Five product additives were prepared in the manner described in ExampleI except that varying amounts of a neutralizing mixture containing 79weight percent lead,

oxide and 21 weight percent lead acetate were used to neutralize the100-gram portions of acid oil. The five product additives thus obtainedwere used to prepare five lubricating oilcompositions in the same mannerand using the same base lubricating oil stock as in Example I. Rustrating tests were then run on said five lubricating oil compositions asdescribed in Example I. The results of these tests are set forth as Runs2 to 6 in Table H below. Run 1 in Table H presents comparable data forvolume the product additive of Run 3 from Table 'I. 55' gjgi iggg f P itSAE stock 64: 5 Table II SAE 50 stock 24 0 Lead petroleum sulinnate gTotal Grams Neutral- Total Meq. or Lubr1zol1360 0.8 Run No. Acidity ofizing Mixture Pb per meq. of Rust santopour C 0. 1'

Acid Oil per 100 grams total acidity Rating 2 wt. percent of Acid on 60100.0

a. 6 14. 2 1. 59 8.5 Engine Rust Ratings 1 4.8 10.6 0.89 3.5 4.8 14.21.18 6.0 4. s 16. 2 1. 36 7. 5 Ratmgs b a ned 4. 3 13, 9 1, 59 9 5 65Rating Items Ratings on Reference 4. s 23. 0 1. 9a 9.8 GMR 063 1 Productwas a gel Cylinder Walls 8.0 7. 5 i I 10 1s a perfect rating igterglunglgrm 8. 0 7. 0

. 't p A graph of the above data plotting rust rating ,vs. f. 38 lg meq.of total Pb/meq. of total acidity shows it is desirable 70 32 52 3 3afigfifis 3-3 g-g to use at least about 1.13 meq. of total Pb/meq. oftotal Push 11:11:: acidity to obtaina product having a rust rating above1 A R 5.5, at least about 1.3 meq. of total Pb/meq. of total vemge Rust3mg 7 9 6 3 acidity to obtain a product having a rust rating of at xRust ratio s made in d least 7, and at least about 1.4 meq. of totalPb/meq. of 75 cu (CRO) acgepted if ifg g Cmrdmatmg Resemh 8. totalacidity to obtain a producthaving a rust rating of at least 7.5.

EXAMPLE HI A carbon spot dispersancy test was carried out on the leadpetroleum sulfonate product additive of Run No. 3 of Table I blended ata 4 percent concentration in a commercial SAE 10 lubricating oil stock.The results of said tests showed the lead petroleum sulfonate additiveproducts of the invention possess excellent detergent properties. In.

EXAMPLE .IV

A 1960 Oldsmobile Sequence H test was carried out on a lubricating oilcontaining a lead petroleum sulfonate additive of the invention preparedessentially. as described above for Run No. 5 in Example II. Said leadpetroleum. sulfonate product additive was blended into a commercial- SAE30 lubricating oil at a concentration of 4.8 volume.

percent.

The 1960 Sequence II test is an integral part of the.

Engine Sequence tests used by industry to describe minimum performancerequirements of crankcase oi-ls forAPI Service MS. These tests have beenapproved by ASTM. They are reviewed and updated periodically tomaintain.

their significance in terms of contemporary field performance. Detaileddescriptions of the Engine Sequence tests are covered in ASTM SpecialTechnical Publication No. 315A, Engine Test Sequences for EvaluatingAutomotive Lubricants for API Service MS; American Society for TestingMaterials, 1916 Race Street, Philadelphia 3, Pa..

The Sequence H test on the experimental lead sulfonate was run inaccordance with test conditions prescribed in this publication.

Said Sequence H test measures anti-rust performance of crankcase motoroils. Relative performance of lubricants is determined by the degree towhich certain engine components are attacked by rust. This level ofengine rust is then compared to rust ratings obtained on a reference 1lubricant (GMR 6063) evaluated in the same laboratory. This referencelubricant is considered by industry to pro- Kqicegninimum acceptableperformance for API Service The results of said Sequence H tests are setforth in Table D1 below.

Table III' 1960 OLDSMOBILE SEQUENCE II TEST RESULTS The data given inthe above Table III show that lubricating oils containing the leadpetroleum sulfonate additives of the invention provide a higher level ofanti-rust protection than that provided by the reference lubricant.

The above pH values and total base number values (TBN) were determinedin accordance with a modification of ASTM D664-58. In this modified test2 grams of the lead petroleum sulfonate product additive are dissolvedin 100 milliliters of a 50/50 mixture of benzene and isopropyl alcoholcontaining 0.5 volume percent water. The mixture is shaken Well and thepH determined using a standard pH meter. If the pH of the said mixtureis above 4, the mixture is then titrated to a pH of 4 using standard 0.1N HCl. From this titration TBN, or total base number, is calculated asfollows:

where V=ml. of HCl, N=normality of HCl, and W=grams of sample. TBN isreported as mg. of KOH per gram of oil.

While certain embodiments of the invention have been described forillustrative purposes, the invention obviously is not limited thereto.Various other modifications will be apparent to those skilled in the artin view of this disclosure. Such modifications are within the spirit andscope of the invention.

I claim:

1. A process for producing a superior lead petroleum sulfonate, usefulas an additive for lubricants, said additive having superior rustinhibiting properties as well as good detergent properties, whichprocess comprises: sulfonating a petroleum hydrocarbon fraction having aviscosity within the range of 90 to 720 SUS at 210 F. and a viscosityindex of at least about 85; neutralizing the reaction product with amixture of lead oxide and lead acetate, said lead oxide being present insaid mixture in an amount suflicient to supply from 12 to 90 weightpercent and said lead acetate being present in said mixture in an amountsufiicient to supply from 88 to' weight percent of the total amount oflead milliequivalents prescut; and recovering the resulting leadpetroleum sulfonate.

2. A process according to claim 1 wherein said petro:

leum hydrocarbon fraction has a viscosity within the range of from 200to 230 SUS at 210 F said lead oxide is present in an amount sufficientto supply from 20 to 88 weight percent and said lead acetate is presentin an amount suflicient to supply from 80 to 12 weight percent of thetotal amount of lead milliequivalents present.

3. A process according to claim 2 wherein said lead oxide is present inan amount sufficient to supply from to 87 weight percent and said leadacetate is present in an amount sufiicient to supply from 50 to 13weight percent of the total amount of lead milliequivalents present, andthe total amount ofsaid lead milliequivalents is sufficient to supply atleast about 1.13 milliequivalents of lead per milliequivalent of totalacidity in said reaction product before neutralization thereof.

4. A process for producing a superior lead petroleum sulfonate additivefor lubricants, said additive having superior rust inhibiting propertiesas well as good detergent properties, which process comprises:sulfonating a petroleum hydrocarbon fraction having a viscosity withinthe range of about 90 to about 720 SUS at 210 F. and a viscosity indexof at least about 85; neutralizing the reaction product with a mixtureof lead oxide and lead acetate, said lead oxide being present in saidmixture in an amount sufficient to supply from 12 to 90 weight percentand said lead acetate being present in said mixture in an amountsufiicient to supply from 88 to 10 weight percent of the total amount oflead milliequivalents present; and recovering a mixture of leadpetroleum sulfonate and unsulfonated oil from said neutralized reactionproduct as said additive.

5. A process according to claim 4 wherein said petroleum hydrocarbonfraction has a viscosity within the range of from 200 to 230 SUS at 210F., said lead oxide is present in an amount sufiicient to supply from 20to 88 weight percent and said lead acetate is present in an amountsuflicient to supply from to 12 weight percent of the total amount oflead milliequivalents present.

6. A process according to claim 5 wherein said lead oxide is present inan amount suflicient to supply from 50 to 87 weight percent and saidlead acetate is present in an amount suflicient to supply from 50 to 13weight percent of the total amount of lead milliequivalents present, andthe total amount of said lead milliequivalents is suflicient to supplyat least about 1.13 milliequivalents of lead per milliequivalent oftotal acidity in said reaction product before neutralization thereof.

7. A process for producing a superior lead petroleum sulfonate additivefor lubricants, said additive having superior rust inhibiting propertiesas Well as good detergent properties, which process comprises:sulfonating one part by weight of a deasphalted and solvent extractedpetroleum fraction having a viscosity within the range of from about 140to about 720 SUS at 210 F., and a viscosity index of at least 85, with'from about 0.02 to 0.2 part by weight of liquid S0 as liquid S0dissolved in liquid S0 neutralizing the reaction product with a mixtureof lead oxide and lead acetate, said lead oxide being present in saidmixture in an amount sufiicient to supply from 12 to 90 weight percentand said lead acetate being present in said mixture in an amountsuflicient to supply from 88 to 10 percent of the total amount of leadmilliequivalents present, and said total amount of lead milliequivalentsbeing sufficient to supply at least about 1.13 milliequivalents of leadper milliequivalent of total acidity in said reaction product; andrecovering a mixture of lead petroleum sulfonate and unsulfonated oilfrom said neutralized reaction product as said additive.

. 8. A process according to claim 7 wherein said petroleum fraction hasa viscosity within the range of from about 200 to about 230 SUS at 210F.

9. A process for producing a superior lead petroleum sulfonate additivefor lubricants, said additive having superior rust inhibiting propertiesas well as good de tergent properties, which process comprises:intimately admixing one part by weight of a deasphalted and solventextracted petroleum fraction having a viscosity within the range of fromabout to about 720 SUS at 210 F., and a viscosity index of at leastabout 85, with from about 0.02 to 0.2 part by weight of liquid S0 asliquid S0 dissolved in liquid S0 removing S0 diluent and any excess S0from the resulting reaction mixture of sulfonic acids and unsulfonatedoil; intimately admixing said diluent-free reaction mixture withhydrocarbon diluent, Water, lead oxide and lead acetate to neutralizesame, said lead oxide being present in an amount sufiicient to supplyfrom 12 to 90 weight percent and said lead acetate being present in anamount suflicient to supply from 88 to 10 weight percent of the totalamount of lead milliequivalents present, and said total amount of leadmilliequivalents being suflicient to supply at least about 1.13milliequivalents of lead per milliequivalent of total acidity in saiddiluent free reaction mixture; heating said thus neutralized reactionmixture to remove substantially all of said water and at least a portionof said hydrocarbon diluent; diluting said dehydrated and neutralizedreaction mixture with another portion of said hydrocarbon diluent andfiltering same to remove inorganic solids; and removing hydrocarbondiluent from the resulting filtrate so as to recover a mixture of leadpetroleum sulfonate and unsulfonated oil as said additive.

10. A process according to claim 9 wherein said petroleum fraction has aviscosity within the range of from about 200 to about 230 SUS at 210 F.

11. A lubricant additive comprising a mixture of lead petroleumsulfonate and the unsulfonated residual oil as- 11 i sociated therewith,said additive having superior rust inhibiting properties as well as gooddetergent properties, which mixture is obtained by: sulfonating apetroleum hydrocarbon fraction having a viscosity, within the range ofabout 90 to about 720 SUS at 210 F. and a viscosity index of at leastabout 85; neutralizing the reaction product with a mixture of lead oxideand lead acetate, said lead oxide being present in said mixture in anamount sufl'lcient to supply from 12 to 90 weight percent and said leadacetate being present in said mixture inan amount suflicient to supplyfrom 88 to 10 weight percent of the total amount of leadmilliequivalents present; and recovering a mixture of lead petroleumsulfonate and unsulfonated oil from said neutralized reaction product assaid additive.

12.,A lubricantadditive comprising a mixture of lead petroleum sulfonateand the unsulfonated residual oil associated therewith, which mixture isobtained by: sulfonating one part by weight of a deasphalted and solventextracted petroleum fraction having a viscosity within the range of fromabout 140 to about 720 SUS at 210 F., and a viscosity index of, at least85, with from about 0.02 to 0.2 part by weight of liquid. S as liquid S0dissolved in liquid 50;; neutralizing the reaction product with amixture of lead oxide and lead acetate, said lead oxide being present insaid mixture in an amount sufiicient to supply frorn'12 to 90 weightpercent and said lead acetate being present in said mixture in an amountsufficient to supply from 88 to weight percent of the total amount oflead milliequivalents present, and said total amount of leadmilliequivalents being suflicient to supply at least about 1.13milliequivalents of lead per milliequivalent of total acidity in saidreaction product; and recovering a mixture of lead petroleum sulfonateand unsulfonated oil from said neutralized reaction product as saidadditive.

13. A lubricating oil composition comprising a petroleum lubricating oilbase stock containing from 0.2 to about 30 weight percent of a leadpetroleum sulfonate additive having superior rust inhibiting propertiesas well as good detergent properties, said additive having been obtainedby: sulfonating a petroleum hydrocarbon fraction having a viscosityWithin the range of 90 to 720 SUS at 210 F. and a viscosity index of atleast about 85; neutralizing the reaction product with a mixture of leadoxide and lead acetate, said lead oxide being present in said mixture inan amount suflicient to supply from 12 to 90 weight percent and saidlead acetate being present in said mixture in an amount sufiicient tosupply from 88 to 10 weight percent of the total amount of leadmilliequivalents present; and recovering the resulting lead petroleumsulfonate.

14. A lubricating oil composition comprising a petroleum lubricating oilbase stock containing from about 2 to about 20 weight percent of a leadpetroleum sulfonate additive having superior'rust inhibiting propertiesas well as good detergent properties, said additive having been obtainedby: sulfonating a petroleum hydrocarbon fraction 12 having a viscositywithin the range of about 90 to about 720 SUS at 210 F. and a viscosityindex of at least about neutralizing the reaction productwith a mixtureof lead oxide and lead acetate, said lead oxide being present in saidmixture in an amount suflicient to supply from 12 to weight percent andsaid lead acetate being present in said mixture in an amount suflicientto supply from 88 to 10 weight percent of the total amount of leadmilliequivalents present; and recovering a mixture of lead petroleumsultonate and unsulfonated oil from said neutralized reaction product assaid additive.

15. 'A lubricating oil composition comprising a petroleum lubricatingoil base stock containing from 0.2 to about 30 weight percent of a leadpetroleum sulfonate additive having superior rust inhibiting propertiesas well as good detergent properties, said additive having been obtainedby: sulfonating one part by weight of a de-- asphalted and solventextracted petroleum fraction having a viscosity within the range of fromabout to about 720 SUS at 210 F., and a viscosity index of at least 85,with from about 0.02 to 0.2 part by weight of liquid S0 as liquid S0dissolved in liquid S0 neutralizing the re.- action product with amixture of lead oxide and lead acetate, said lead oxide being present insaid mixture in i an amount suflicient to supply from 12 to 90 weightpercent and said lead acetate being present in said mixture. in anamount sufficient to supply from 88 to 10 weight percent of the totalamount of lead milliequivalents prescut, and said total'amount of leadmilliequivalents being sufiicient to supply at least about 1.13milliequivalents of lead per milliequivalent of total acidity in saidreaction product; and recovering a mixture of lead petroleum sulcositywithin the range of 90 to 720 SUS at 210 F. and a viscosity index of atleast about 85; neutralizing the re-' 1 action product by simultaneouslycontacting same with both lead oxide and lead acetate, said oxide andsaid acetate being present during said contacting in amounts sufficientto supply from 12 to 90 and from 88 to 10 weight percent respectively ofthe total amount of lead milliequivalents present; and recovering theresulting lead petroleum sulfonate.

References Cited by the Examiner UNITED STATES PATENTS I 1,871,9418/1932 Arveson 25233 2,501,732 3/1950 Mertes 25233 2,865,957 12/1958Logan 260-435 X DANIEL E. WYMAN, Primary Examiner. C. F. DEES, AssistantExaminer.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patnet N06 3, 277,004 October 4, 1966 Sidney Schiff It is hereby certified that errorappears in the above numbered patent requiring correction and that thesaid Letters Patent should read as corrected below.

Column 10, line 31, before "percent" insert weight column 11, line 18,before "which" insert said additive having superior rust inhibitingproperties as well as good detergent properties,

Signed and sealed this 5th day of September 1967.

(SEAL) Attest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner ofPatents

13. A LUBRICATING OIL COMPOSITION COMPRISING A PETROLEUM LUBRICATING OUL BASE STOCK CONTAINING FROM 0.2 TO ABOUT 30 WEIGHT PERCENT OF A LEAD PETROLEUM, SULFONATE ADDITIVE HAVING SUPERIOR RUST INHIBITING PROPERTIES AS WELL AS GOOD DETERGENT PROPERTIES, SAID ADDITIVE HAVING BEEN OBTAINED BY: SULFONATING A PETROLEUM HYDROCARBON FRACTION HAVING A VISCOSITY WITHIN THE RANGE OF 90 TO 720 SUS AT 210*F. AND A VISCOSITY INDEX OF AT LEAST ABOUT 85; NEUTRALIZING THE REACTION PRODUCT WITH A MIXTURE OF LEAD OXIDE AND LEAD ACETATE, SAID LEAD OXIDE BEING PRESENT IN SAID MIXTURE IN AN AMOUNT SUFFICIENT TO SUPPLY FROM 12 TO 90 WEIGHT PERCENT AND SAID LEAD ACETATE BEING PRESENT IN SAID MIXTURE IN AN AMOUNT SUFFFICIENT TO SUPPLY FROM 88 TO 1 WEIGHT PERCENT OF THE TOTAL AMOUNT OF LEAD MILLIEQUIVA LENTS PRESENT; AND RECOVERING THE RESULTING LEAD PETROLEUM SULFONATE. 